1. Technical Field
The present invention relates to a liquid supply apparatus that supplies a liquid such as ink, and a liquid ejection apparatus such as an inkjet printer that ejects a liquid supplied from a liquid supply apparatus.
2. Related Art
There has been known to be a liquid ejection system (liquid ejection apparatus) including an ink tank (liquid supply apparatus) in which a liquid injection path (liquid injection portion) for injecting ink (a liquid) into a liquid containing chamber is formed (e.g., JP-A-2011-240707). The ink tank is provided such that its orientation can be changed. That is, ink is injected through the liquid injection path in an injection state in which the liquid injection path is open facing upward, and the ink tank supplies ink to a recording head (liquid ejecting portion) in a usage state in which the liquid injection path is open facing a horizontal direction.
Also, an air introduction port, which is one end of an air exposing flow path having another end that communicates with the atmosphere, is formed in the liquid containing chamber. The air introduction port is formed at a position located at a bottom portion when the ink tank is in the usage state, and a position located above the liquid surface of the ink when the ink tank is in the injection state. For this reason, when the ink tank into which the liquid was injected in the injection state is put in the usage state, an air contact liquid surface (meniscus) is formed near the air introduction port and a suitable hydraulic head difference is maintained between the ink tank and the recording head that ejects the ink.
JP-A-2011-240707 is an example of related art.
Incidentally, with this kind of ink tank, if ink is erroneously injected into the ink tank during the usage state, the ink will flow from the air introduction port to the air exposing flow path. Upon doing so, the principle of Mariotte's bottle cannot be used, the hydraulic head difference between the ink tank and the recording head will change, and thereby the supply of ink will become unstable.
Also, when ink flows into the air exposing flow path in this manner and an air contact liquid surface is formed at a position located away from the air introduction port, the air contact liquid surface cannot be returned to the vicinity of the air introduction port unless an amount of ink corresponding to the amount that flows into the air exposing flow path is supplied to the recording head.
Note that this problem is not limited to a liquid ejection system that ejects ink supplied from an ink tank that includes a liquid injection path, but is roughly the same for a liquid ejection apparatus that ejects liquid supplied from a liquid supply apparatus that includes a liquid injection portion.